沿空留巷围岩“大、小结构”稳定性动态演化机理分类研究

The stability of big and small structures around gob-side entry retaining is characterized by significant spatiotemporal evolution, and therefore keeping mutual coordination deformation between big and small structures is crucial to controlling surrounding rock around gob-side entry retaining. In this study, firstly, based on the classification of overlying strata structures, the active control mechanism of roadside support and deep cutting along roadway over strata movement deformation and strata stress is studied; secondly, the mechanical model of big structure is constructed to determine the stability criterion of big structure, and quantitative relationships between instability coefficient of big structure and parameters such as small structure’s parameters and the parameters of deep cutting along roadway are explored; thirdly, the sensitivity of influence factors of big structure’s stability is analyzed. Accordingly, mutual coordination deformation mechanism between big and small structures is developed. At the outset, small structure’s microscopic damage is studied and model test, laboratory test, etc. are employed to study small structure’s stress-strain evolutionary characters in different periods of gob-side entry retaining, to define damage tensors reflecting small structure’s stress-strain evolutionary characters, to deduce small structure’s damage evolution equation and damage constitutive relations, and to determine small structure’s damage instability criterion. Then, Bifurcation Theory is applied to establishing the big structure system’s mutation model at the late stage of gob-side entry retaining; influence of small structure’s damage evolution on model mutation of big structure system is studied and controlling conditions of system mutation are determined. Based on the above studies, a prediction model of chaotic time series is established to forecast mutation instability time of the system, providing the guidance for classified controlling of surrounding rock around gob-side entry retaining.

沿空留巷围岩“大、小结构”稳定性具有显著的时空演化特征，保持其相互协调变形至关重要。基于覆岩结构分类，研究巷旁支护、巷旁深切缝对岩层移动变形和岩层应力主动控制作用机理，构建“大结构”力学模型，确定其稳定性力学判据，寻求“小结构”参数、巷旁深切缝参数等与“大结构”失稳系数之间的定量关系，分析“大结构”稳定性影响因素敏感性，揭示“大、小结构”相互协调变形机理。从“小结构”细观损伤研究入手，采用模型试验、实验室测试等，研究不同时期“小结构”内部应力应变演化特征，定义能够反映应力应变演化特征的损伤张量，推导“小结构”损伤演化方程及其损伤本构关系，确定其损伤失稳判据。应用突变分岔理论，构建沿空留巷后期“大结构”系统突变模型，研究“小结构”损伤演化对系统突变影响，确定系统发生突变时外界控制条件，基于此，构建混沌时间序列预测模型，预测系统突变失稳时间，为沿空留巷围岩分类防控提供依据。

沿空留巷围岩“大、小结构”稳定性具有显著的时空演化特征，保持其相互协调变形至关重要。基于覆岩结构分类，研究巷旁支护、巷旁深切缝对岩层移动变形和岩层应力主动控制作用机理，构建“大结构”力学模型，确定其稳定性力学判据，寻求“小结构”参数、巷旁深切缝参数等与“大结构”失稳系数之间的定量关系，分析“大结构”稳定性影响因素敏感性，揭示“大、小结构”相互协调变形机理。从“小结构”细观损伤研究入手，采用模型试验、实验室测试等，研究不同时期“小结构”内部应力应变演化特征，定义能够反映应力应变演化特征的损伤张量，推导“小结构”损伤演化方程及其损伤本构关系，确定其损伤失稳判据。应用突变分岔理论，构建沿空留巷后期“大结构”系统突变模型，研究“小结构”损伤演化对系统突变影响，确定系统发生突变时外界控制条件，基于此，构建混沌时间序列预测模型，预测系统突变失稳时间，为沿空留巷围岩分类防控提供依据。